Rule 56 states:
"Dogs. Do not let a dog out on the road on its own. Keep it on a short lead when walking on the pavement, road or path shared with cyclists or horse riders."
https://www.highwaycodeuk.co.uk/rules-about-animals-other-animals.html
In principle, this is a good rule. And it may or may not be useful in civil disputes.
However, in practice it is widely ignored and TBH, I expect that most have never heard of it. On inadvisably stopping to politely advise dog walkers of the rule, I have received replies that "It's a path, it doesn't apply" and "My dog likes to roam free". I haven't yet had a better defence such as "it's the dog that taking me for a walk", which may also be nearer the truth.
Anyway, given the lack of knowledge of this rule, I propose its abolishment on the grounds that it just causes people like me, who like rules followed, lots of stress. It's bad enough on the roads - nice to get away from the stress by going off-road.